CN112012948B

CN112012948B - Counter-rotating fan structure

Info

Publication number: CN112012948B
Application number: CN201910466341.0A
Authority: CN
Inventors: 陈建宏; 杨朝富; 黄建智; 黄躍龙; 张楯成
Original assignee: Delta Electronics Inc
Current assignee: Delta Electronics Inc
Priority date: 2019-05-31
Filing date: 2019-05-31
Publication date: 2022-11-18
Anticipated expiration: 2039-05-31
Also published as: US20200378388A1; CN112012948A; US11078915B2

Abstract

A counter-rotating fan structure comprises a first base, a first fan, a second base and a second fan. The first fan is rotatably arranged on the first base and comprises a first hub. The first hub has a first maximum width. The second fan is rotatably arranged on the second base and comprises a second hub. The second hub has a second maximum width. The first base and the second base are positioned between the first fan and the second fan. The second maximum width is greater than the first maximum width.

Description

Counter-rotating fan structure

Technical Field

The present invention relates to a fan structure, and more particularly, to a counter-rotating fan structure.

Background

With the rapid development of electronic products toward high performance, high frequency, high speed and light weight, the heating temperature of electronic products is higher and higher, so that the instability phenomenon is easily generated, and the reliability of the products is affected. Therefore, heat dissipation has become one of the important issues in the development of electronic products.

Nowadays, a fan is a common design for a heat dissipation device in an electronic product, but a single fan is not enough to dissipate heat efficiently for an electronic product generating a large amount of heat, and in addition, in order to avoid the interruption of the operation of the heat dissipation device due to the failure of the single fan, a plurality of fans are generally used at the same time to achieve the purpose of increasing the air volume of air flow. Wherein the plurality of fans are axial fans.

However, when the two fans are assembled in series but the structural configuration is not designed well, the air-out performances of the two fans may be influenced and interfered with each other. That is, the fan connected in series does not have additive effect, but may cause negative effect.

Therefore, how to provide a fan structure capable of solving the above problems is one of the problems that the industry needs to invest in research and development resources to solve.

Disclosure of Invention

In view of the above, an objective of the present invention is to provide a counter-rotating fan structure that can effectively solve the above-mentioned problems.

To achieve the above objective, according to one embodiment of the present invention, a counter-rotating fan structure includes a first base, a first fan, a second base and a second fan. The first fan is rotatably arranged on the first base and comprises a first hub. The first hub has a first maximum width. The second fan is rotatably disposed on the second base and includes a second hub. The second hub has a second maximum width. The first base and the second base are positioned between the first fan and the second fan. The second maximum width is greater than the first maximum width.

In one or more embodiments of the present invention, the first base has a third maximum width, the second base has a fourth maximum width, and the second maximum width, the third maximum width and the fourth maximum width are both between the first maximum width and the second maximum width.

In one or more embodiments of the present invention, the third maximum width is equal to the fourth maximum width.

In one or more embodiments of the present invention, the third maximum width is greater than or equal to the first maximum width. The fourth maximum width is greater than or equal to the third maximum width. The second maximum width is greater than the fourth maximum width.

In one or more embodiments of the present invention, the third maximum width is greater than the first maximum width. The fourth maximum width is greater than or equal to the third maximum width. The second maximum width is greater than or equal to the fourth maximum width.

In one or more embodiments of the present invention, the second fan is configured to rotate on an axis. The second hub has an outer edge contour in a cross-section through the axis. The outer edge contour line is provided with an inclined section which is inclined relative to the axis.

In one or more embodiments of the present invention, the outer contour further has parallel segments. The parallel section is connected with the inclined section, is parallel to the axis and is far away from the second base compared with the inclined section.

In one or more embodiments of the present invention, the first fan is configured to rotate on an axis. The first hub has an outer edge contour in a cross-section through the axis. The outer edge contour line has an inclined section inclined relative to the axis.

In one or more embodiments of the present invention, the outer contour further has parallel segments. The parallel section is connected with the inclined section, is parallel to the axis and is closer to the first base than the inclined section.

In one or more embodiments of the present invention, a ratio of a height of the parallel section to a height of the outer contour line in a direction parallel to the axis is substantially between 0.2 and 0.85.

In one or more embodiments of the present invention, the inclined section is a straight line or a curved line.

In one or more embodiments of the present invention, the counter-rotating fan structure further includes a plurality of first vanes and a plurality of second vanes. The first stationary blade is connected to an outer edge of the first base. The second stationary blade is connected to an outer edge of the second base. The first vane and the second vane have a corresponding positional relationship with each other. The connected first and second vanes form a plurality of combined vanes.

In one or more embodiments of the present invention, the first base has a center. The outer edge of the first base to which the first vane is connected has a root. The root of the first vane has a plurality of central angles to the center, and the angles of at least two of the central angles are different from each other.

In summary, in the counter-rotating fan structure of the present invention, the first fan and the second fan are operated in a counter-rotating manner (i.e. the rotating directions are opposite), so that the air entering the counter-rotating fan structure is pressurized between the first fan and the second fan, thereby increasing the outlet air speed and effectively increasing the heat dissipation capability. In addition, the shape of the hub of the first fan is designed to be asymmetrical to the shape of the hub of the second fan in the direction of the rotation axis (for example, the maximum width of the hub of the second fan is made larger than the maximum width of the hub of the first fan), so that the performance of the counter-rotating fan structure of the present invention in terms of high and low impedance can be effectively improved. In addition, the shape of the hub of the second fan is designed asymmetrically in the direction of the rotation axis (for example, the outer edge contour line of the hub of the second fan is designed with an inclined section), which also contributes to improving the performance of the counter-rotating fan structure of the invention in medium and high impedance.

The foregoing is merely illustrative of the problems to be solved, solutions to problems, and effects produced by the present invention, and specific details thereof are set forth in the following description and the related drawings.

Drawings

These and other objects, features, advantages and embodiments of the present invention will become more apparent from the following detailed description of the preferred embodiments of the invention when taken in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a counter-rotating fan according to an embodiment of the present invention;

FIG. 2 is a perspective exploded view of the counter-rotating fan shown in FIG. 1;

FIG. 3 is a cross-sectional view of the counter-rotating fan structure shown in FIG. 1 along line 3-3;

FIG. 4 is a graph illustrating characteristics of a counter-rotating fan according to an embodiment of the present invention under different design parameters;

fig. 5 is a bottom view showing the first housing of fig. 1.

[ notation ] to show

100: counter-rotating fan structure

110: first shell

111: first outer wall

112: first base

112a: perforation

113: first stationary blade

113a: root of a tree

120: first fan

121: first wheel hub

121a, 141a: outer edge contour line

121a1, 141a1: inclined section

121a2, 141a2: parallel section

122: first fan blade

130: second shell

131: second outer wall

132: second base

133: second stationary blade

140: second fan

141: second wheel hub

142: second fan blade

A: axial line

C: center (C)

FH. FSH, RH, RSH: height

L1, L2, L3, L4: curve line

W1: first maximum width

W2: second maximum width

W3: third maximum width

W4: fourth maximum width

θ 1, θ 2, θ 3: centre angle

Detailed Description

Please refer to fig. 1 to 3. Fig. 1 is a perspective assembly view illustrating a counter-rotating fan structure 100 according to an embodiment of the invention. Fig. 2 is an exploded perspective view of the counter-rotating fan structure 100 shown in fig. 1. Fig. 3 is a cross-sectional view of the counter-rotating fan structure 100 of fig. 1 along the line 3-3. The arrow directions shown in fig. 1 to 3 represent the air inlet and outlet directions of the counter-rotating fan. As shown in fig. 1 and fig. 2, in the present embodiment, the counter-rotating fan structure 100 includes a first casing 110, a first fan 120, a second casing 130 and a second fan 140. The structure and function of each component included in the counter-rotating fan structure 100 and the connection relationship between the components will be described in detail below.

As shown in fig. 2, in the present embodiment, the first casing 110 includes a first outer wall 111, a first base 112, and a plurality of first vanes 113. The first outer wall 111 is hollow and has two opposite openings. The first base 112 is located at one of the openings of the first outer wall 111. The first vane 113 is substantially radially connected between an inner edge of the first outer wall 111 and an outer edge of the first base 112. In the embodiment shown in FIG. 2, the number of the first vanes 113 is 3, but the invention is not limited thereto and can be flexibly modified according to actual requirements.

As shown in fig. 2, in the present embodiment, the first fan 120 is accommodated in the first outer wall 111 (refer to fig. 3) and is rotatably disposed on the first base 112. Specifically, the first fan 120 includes a first hub 121 and a plurality of first blades 122. The first hub 121 is rotatably coupled (e.g., via a pivot) to the first base 112 based on an axis a (see fig. 3). The first fan blades 122 are connected to an outer edge of the first hub 121, and configured to introduce air outside the first casing 110 into the first casing 110 and guide the introduced air to the second casing 130 via the first vanes 113 when the first fan 120 rotates relative to the first casing 110. In the embodiment shown in fig. 2, the number of the first blades 122 is 5, but the invention is not limited thereto and can be flexibly modified according to actual requirements.

As shown in fig. 2 and 3, in the present embodiment, the second casing 130 includes a second outer wall 131, a second base 132, and a plurality of second vanes 133 (only 1 vane is shown in the cross-sectional view of fig. 3). The second outer wall 131 is hollow and has two opposite openings. The second base 132 is located at one of the openings of the second outer wall 131 and abuts against the first base 112, so that the first base 112 and the second base 132 can also be regarded as a combined base. The second vane 133 is substantially radially connected between an inner edge of the second outer wall 131 and an outer edge of the second base 132. In the present embodiment, the number of the second vanes 133 is the same as that of the first vanes 113 (i.e., 3). In some embodiments, the first vane 113 and the second vane 133 have a corresponding positional relationship with each other, such that when the first casing 110 and the second casing 130 are connected, the second vane 133 is also connected to the corresponding first vane 113, so that the connected first vane 113 and second vane 133 can form a plurality of combined vanes. In some embodiments, the first vane 113 and the second vane 133 may also be replaced with ribs.

In some embodiments, the first housing 110 and the second housing 130 can be a single structure made of the same material (e.g., made of plastic by an injection molding process).

As shown in fig. 2 and 3, in the present embodiment, the second fan 140 is accommodated in the second outer wall 131 and is rotatably disposed on the second base 132. Specifically, the second fan 140 includes a second hub 141 and a plurality of second blades 142. The second hub 141 is rotatably coupled to the second base 132 (e.g., via a pivot) based on an axis a. The first base 112 and the second base 132 are located between the first fan 120 and the second fan 140. The second fan blades 142 are connected to the outer edge of the second hub 141 and configured to guide the air flowing into the second casing 130 (i.e., the air guided by the first vanes 113 of the first casing 110) into the second casing 130 through the second vanes 133 when the second fan 140 rotates relative to the second casing 130, so that the introduced air is discharged out of the second casing 130 from the opening of the second outer wall 131 away from the second base 132. In the embodiment shown in fig. 2, the number of the second blades 142 is 4, but the invention is not limited thereto and can be flexibly modified according to actual requirements.

It should be noted that, in the present embodiment, the first fan 120 and the second fan 140 are operated in a counter-rotating manner (i.e. the rotating directions are opposite), so that the air entering the counter-rotating fan structure 100 is pressurized between the first fan 120 and the second fan 140, thereby increasing the outlet air speed and effectively enhancing the heat dissipation capability.

As shown in fig. 3, in the present embodiment, the first hub 121 has a first maximum width W1, the second hub 141 has a second maximum width W2, the first base 112 has a third maximum width W3, and the second base 132 has a fourth maximum width W4, and the second maximum width W2 is greater than the first maximum width W1, while the third maximum width W3 and the fourth maximum width W4 are both between the first maximum width W1 and the second maximum width W2. It can be seen that the shape of the first hub 121 of the first fan 120 is asymmetric with respect to the shape of the second hub 141 of the second fan 140 in a direction parallel to the axis a. With this configuration, the performance of the counter-rotating fan structure 100 of the present embodiment in medium and high impedance can be effectively improved, for the following reason, refer to the description of fig. 4.

Referring to fig. 4, a characteristic curve diagram of the counter-rotating fan structure 100 according to an embodiment of the invention under different design parameters is shown. As shown in fig. 4, the curves L1 and L3 represent the flow-pressure curve and the flow-power curve respectively tested by the asymmetric design (i.e., the second maximum width W2 is greater than the first maximum width W1) of the counter-rotating fan structure 100 shown in fig. 1, wherein the rotation speeds of the first fan 120 and the second fan 140 are 19,500rpm (Revolutions Per Minute) and 18,500rpm, respectively. Curves L2 and L4 respectively represent a flow-pressure curve and a flow-power curve tested by a symmetrical design in which the counter-rotating fan structure 100 shown in fig. 1 is modified to have the same width for the first maximum width W1, the second maximum width W2, the third maximum width W3, and the fourth maximum width W4, wherein the rotation speeds of the first fan 120 and the second fan 140 are 24,300rpm and 27,200rpm, respectively. For applications with medium to high impedance (e.g., flow rates between about 20CFM (flow Per Minute) and about 40 CFM), taking the flow-pressure conditions indicated by the triangles in fig. 4 as an example, the fan speed of the counter-rotating fan structure 100 with the symmetrical design needs to be high (i.e., 24,300rpm and 27,200rpm), and the power needs to be as high as about 90 watts (Watt) to meet the medium to high impedance application. However, when the asymmetric counter-rotating fan structure 100 shown in fig. 1 is adopted, the rotation speeds of the first fan 120 and the second fan 140 need to be only 19,500rpm (about 20% reduction) and 18,500rpm (about 32% reduction), respectively, and the power needs to be only about 75 watts (about 17% reduction), which can satisfy the medium-high impedance application. Therefore, the counter-rotating fan structure 100 of the present embodiment has better performance in medium and high impedance.

Referring back to fig. 3, in the present embodiment, the third maximum width W3 and the fourth maximum width W4 are both between the first maximum width W1 and the second maximum width W2, and the third maximum width W3 is equal to the fourth maximum width W4. In some embodiments, the third maximum width W3 is greater than or equal to the first maximum width W1, the fourth maximum width W4 is greater than or equal to the third maximum width W3, and the second maximum width W2 is greater than the fourth maximum width W4. In some embodiments, the third maximum width W3 is greater than the first maximum width W1, the fourth maximum width W4 is greater than or equal to the third maximum width W3, and the second maximum width W2 is greater than or equal to the fourth maximum width W4. In some embodiments, the first maximum width W1, the third maximum width W3, the fourth maximum width W4, and the second maximum width W2 are sequentially increasing from one another.

In the cross-sectional view of fig. 3, the second hub 141 has an outer edge contour 141a. The outer edge contour 141a has an inclined section 141a1 and a parallel section 141a2. The inclined section 141a1 is inclined with respect to the axis a. The parallel portion 141a2 is connected to the inclined portion 141a1, and is parallel to the axis a, and is further away from the second base 132 than the inclined portion 141a1, and the portion of the second blade 142 connected to the outer edge of the second hub 141 includes the inclined portion 141a1 and the parallel portion 141a2. It can be seen that the shape of the second hub 141 of the second fan 140 is asymmetric in a direction parallel to the axis a. This configuration also helps to improve the performance of the counter-rotating fan structure 100 of the present embodiment in medium and high impedance.

In some embodiments, as shown in fig. 3, the ratio of the height RSH of the parallel segment 141a2 to the height RH of the outer edge contour 141a in the direction parallel to the axis a is substantially between 0.2 and 0.85. If the ratio is greater than 0.85, the airflow is likely to directly impact the second hub 141, thereby reducing the flow guiding. If the ratio is less than 0.2, the outer contour 141a is similar to a design in which the whole section is an inclined section, and the air pressurization effect may be insignificant or negative.

Also shown in fig. 3, the first hub 121 has an outer periphery profile 121a. The outer edge contour 121a has an inclined segment 121a1 and a parallel segment 121a2. The inclined section 121a1 is inclined with respect to the axis a. The parallel section 121a2 is connected to the inclined section 121a1, is parallel to the axis a, and is closer to the first base 112 than the inclined section 121a 1. Meanwhile, the portion of the first blade 122 connected to the outer edge of the first hub 121 includes an inclined segment 121a1 and a parallel segment 121a2. It can be seen that the shape of the first hub 121 of the first fan 120 is asymmetric in the direction parallel to the axis a.

As shown in fig. 3, in the present embodiment, the inclined section 141a1 is a straight line, and the inclined section 121a1 is a curved line, but the present invention is not limited thereto. In practical applications, the inclined section 141a1 may be curved, and the inclined section 121a1 may be straight.

In some embodiments, as shown in fig. 3, the ratio of the height FSH of the parallel segment 121a2 to the height FH of the outer edge contour 121a in the direction parallel to the axis a is substantially between 0.2 and 0.85. If the ratio is greater than 0.85, the outer contour 121a is similar to a parallel design, resulting in a reduction of the air inlet area and the efficiency of the first hub 121 to direct the airflow. If the ratio is less than 0.2, the outer contour 121a is similar to a design in which the whole section is an inclined section, and as a result, the first hub 121 cannot be mounted on the iron shell inside the hub.

Referring to fig. 5, a bottom view of the first housing 110 in fig. 1 is shown. As shown in fig. 2 and 5, the first base 112 has a center C and a through hole 112a. The through holes 112a are used for routing the internal circuits of the fan structure 100. The first vane 113 has a root portion 113a connected to the first base 112. The root 113a (e.g., the midpoint of the root 113 a) forms a plurality of central angles θ 1, θ 2, θ 3 to the center C of the first base 112, and at least two of the central angles θ 1, θ 2, θ 3 are different from each other. For example, the through hole 112a is formed at a portion of the first base 112 corresponding to the central angle θ 1, and thus the structural strength of the portion of the first base 112 may be affected. By designing the central angle θ 1 (e.g., about 100 degrees) to be smaller than the central angles θ 2 and θ 3 (e.g., about 130 degrees), the central angle θ 1 corresponding to the through hole 112a has the smallest angle, so that the structural strength of the portion of the first base 112 corresponding to the central angle θ 1 can be effectively enhanced.

As is apparent from the above description of the embodiments of the present invention, in the counter-rotating fan structure of the present invention, the first fan and the second fan are operated in a counter-rotating manner (i.e. the rotating directions are opposite), so that air entering the counter-rotating fan structure is pressurized between the first fan and the second fan, thereby increasing the outlet air speed and effectively increasing the heat dissipation capability. In addition, the shape of the hub of the first fan is designed asymmetrically with respect to the shape of the hub of the second fan in the direction of the rotation axis (for example, the maximum widths of the hubs of the first fan and the second fan are designed incrementally), so that the performance of the counter-rotating fan structure of the present invention in terms of medium and high impedance can be effectively improved. In addition, the shape of the hub of the second fan is designed asymmetrically in the direction of the rotation axis (for example, the outer edge contour line of the hub of the second fan is designed with an inclined section), which also contributes to improving the performance of the counter-rotating fan structure of the invention in terms of medium and high impedance.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A counter-rotating fan structure, comprising:

a first base;

a first fan rotatably disposed on the first base and including a first hub having a first maximum width;

a second base; and

a second fan rotatably disposed on the second base and including a second hub having a second maximum width,

the second fan is configured to rotate on the basis of an axis, and the second hub has an outer edge contour line on a section passing through the axis, and the outer edge contour line has an inclined section and a parallel section, the inclined section is inclined relative to the axis,

the first base and the second base are positioned between the first fan and the second fan, the first base is provided with a third maximum width, the second base is provided with a fourth maximum width, the second maximum width is larger than the first maximum width, and the third maximum width and the fourth maximum width are both between the first maximum width and the second maximum width.

2. The counter-rotating fan structure according to claim 1, wherein the third maximum width is equal to the fourth maximum width.

3. The counter-rotating fan structure according to claim 1, wherein the third maximum width is greater than or equal to the first maximum width, the fourth maximum width is greater than or equal to the third maximum width, and the second maximum width is greater than the fourth maximum width.

4. The fan structure of claim 1, wherein the third maximum width is greater than the first maximum width, the fourth maximum width is greater than or equal to the third maximum width, and the second maximum width is greater than or equal to the fourth maximum width.

5. The counter-rotating fan structure according to claim 1, wherein the parallel portion is connected to the inclined portion, parallel to the axis, and further away from the second base than the inclined portion.

6. The contra-rotating fan structure according to claim 1, wherein the first fan is configured to rotate about an axis, and the first hub has an outer edge contour having an inclined section inclined with respect to the axis in a cross section passing through the axis.

7. The fan assembly of claim 6, wherein the outer contour further comprises a parallel portion connected to the inclined portion, parallel to the axis, and closer to the first base than the inclined portion.

8. The contra-rotating fan structure according to claim 5 or 7, wherein a ratio of a height of the parallel section to a height of the outer contour line in a direction parallel to the axis is between 0.2 and 0.85.

9. The structure of a contra-rotating fan according to any one of claims 1 to 7, wherein the inclined section is a straight line or a curved line.

10. The counter-rotating fan structure according to claim 1, further comprising a plurality of first vanes connected to an outer edge of the first base and a plurality of second vanes connected to an outer edge of the second base, the plurality of first vanes and the plurality of second vanes having a corresponding positional relationship with each other, and the plurality of connected first vanes and the plurality of second vanes forming a plurality of combined vanes.

11. The counter-rotating fan structure according to claim 10, wherein the first base has a center, the first base to which the first vanes are connected has a root at each outer edge thereof, the roots of the first vanes to the center have a plurality of central angles, and at least two of the central angles are different from each other.